Leading and trailing edge stitch tab scrap strippers

Abstract

Leading and trailing edge stitch tab scrap strippers utilize pivot arms which are secured to die block bodies for pivotable motion intermediate their two ends. One end of each arm is adapted to engage a stitch tab scrap portion to be stripped and to effect the removal of the tab scrap from a box blank from which it has been cut. A biasing force is applied against a second end of the pivot arm. The pivot arm is caused to pivot in response to the rotation of an upper male slotting head and a lower die cutting anvil. This pivotal movement is effective to strip or to eject the severed stitch tab scrap.

1. A stitch tab scrap stripper and die comprising:
 a pivot arm having a stripper segment and a biasing segment; 
 a pivot shaft on said pivot arm intermediate said stripper segment and said biasing segment, said pivot shaft pivotably securing said pivot arm to a stitch tab die cutting block, said stitch tab die cutting block being securable to a slotter roller of a box blank slotter; 
 biasing means engaging said biasing segment of said pivot arm and exerting a biasing force on said biasing segment, said biasing force opposing movement of said stripper segment with respect to said stitch tab die cutting block about said pivot shaft; and 
 stitch tab scrap engaging means on said stripper segment and spaced from said pivot shaft, said stripper segment of said pivot arm acting to eject a stitch tab scrab severed from a box blank in response to movement of said biasing segment about said pivot shaft, said stripper segment being moved away from said stitch tab die cutting block during rotation of the slotter roller of the box blank slotter. 
 
   
   
     2. The stitch tab scrap stripper of  claim 1  further including a journal on said pivot arm, said journal supporting said pivot shaft. 
   
   
     3. The stitch tab scrap stripper of  claim 1  wherein said biasing means includes a resilient member. 
   
   
     4. The stitch tab scrap stripper of  claim 3  wherein said resilient member is a resilient strip. 
   
   
     5. The stitch tab scrap stripper of  claim 3  wherein said resilient member is a spring. 
   
   
     6. The stitch tab scrap stripper of  claim 3  further including a biasing stud connecting said resilient member to said stitch tab a die cutting block. 
   
   
     7. The stitch tab scrap stripper of  claim 6  wherein said resilient member is a coil spring. 
   
   
     8. The stitch tab scrap stripper of  claim 7  wherein said biasing segment has a free end spaced from said pivot shaft, and a hole at said free end, said biasing stud passing through said hole. 
   
   
     9. The stitch tab scrap stripper of  claim 8  wherein said coil spring is positioned about said bolt and contacting said free end of said biasing segment. 
   
   
     10. The stitch tab scrap stripper of  claim 7  further including a spring retainer block. 
   
   
     11. The stitch tab scrap stripper of  claim 10  wherein said coil spring is positioned intermediate said spring retainer block and said biasing segment of said pivot arm. 
   
   
     12. The stitch tab scrap stripper of  claim 1  further including a fulcrum block on said biasing segment of said pivot arm. 
   
   
     13. The stitch tab scrap stripper of  claim 1  wherein said stripper segment and said biasing segment are co-planar. 
   
   
     14. The stitch tab scrap stripper of  claim 1  wherein said stripper segment and said biasing segment are not co-planar. 
   
   
     15. The stitch tab scrap stripper of  claim 1  wherein said stitch tab scrap engaging means is at least one stripper pin positionable adjacent an outboard end of said stripper segment. 
   
   
     16. A stitch tab scrap stripper comprising:
 a pivot arm having a stripper segment and a biasing segment; 
 a pivot shaft on said pivot arm intermediate said stripper segment and said biasing segment, said pivot shaft being adapted to pivotably secure said pivot arm to a die block; 
 biasing means engaging said biasing segment and exerting a biasing force on said biasing segment, said biasing force opposing movement of said stripper segment about said pivot shaft; 
 stitch tab scrap engaging means on said stripper segment and spaced from said pivot shaft; 
 a fulcrum block on said biasing segment of said pivot arm; and 
 a leading, sloped camming surface on said fulcrum block and a trailing, planar camming surface on said fulcrum block. 
 
   
   
     17. A stitch tab scrap stripper and die adapted for use in stripping stitch tab scraps severed from box blanks in a rotary box blank slotter comprising:
 a stitch tab die cutting block securable to a rotary male slotter head, said stitch tab die cutting block having a die block body; 
 a stitch tab cutting knife mounted in said die block body; 
 a pivot arm secured to said die block body, said pivot arm including a stripper segment having a first free end and a biasing segment having a second free end; 
 a pivot connection between said pivot arm and said die block body, said pivot connection separating said pivot arm into said stripper segment and said biasing segment; and 
 biasing means engaging said die block body and said biasing segment of said pivot arm, said biasing means exerting a force on said biasing segment and opposing movement of said stripper segment with respect to said die block body, said movement of said stripper segment with respect to said die block body acting to eject a stitch tab scrap severed from the box blank by said stitch tab cutting knife in response to said movement of said stripper segment during rotation of the rotary male slotter head of the rotary box blank slotter. 
 
   
   
     18. The stitch tab scrap stripper of  claim 17  wherein said biasing means moves said stripper segment in a stitch tab scrap stripping direction. 
   
   
     19. A stitch tab scrap stripper and die adapted for use in stripping stitch tab scraps from box blanks comprising:
 a die block adapted to be secured to a male slotter head and having a die block body; 
 a stitch tab cutting knife mounted in said die block body; 
 a pivot arm secured to said die block body, said pivot arm including a stripper segment having a first free end and a biasing segment having a second free end, said first free end of said pivot arm being adjacent said stitch tab cutting knife; 
 a pivot connection between said pivot arm and said die block body, said pivot connection separating said pivot arm into said stripper segment and said biasing segment; and 
 biasing means engaging said die block body and said biasing segment said biasing means opposing movement of said stripper segment. 
 
   
   
     20. A stitch tab scrap stripper and die adapted for use in stripping stitch tab scraps from box blanks comprising:
 a die block adapted to be secured to a male slotter head and having a die block body; 
 a stitch tab cutting knife mounted in said die block body; 
 a pivot arm secured to said die block body, said pivot arm including a stripper segment having a first free end and a biasing segment having a second free end; 
 box blank engaging means on said first free end of said pivot arm; 
 a pivot connection between said pivot arm and said die block body, said pivot connection separating said pivot arm into said stripper segment and said biasing segment; and 
 biasing means engaging said die block body and said biasing segment, said biasing means opposing movement of said stripper segment.